Stop motion mechanism for circular knitting machines



June 26, 1962 w. R. SLAGLE 3,040,550

STOP MOTION MECHANISM FOR CIRCULAR KNITTING MACHINES Filed Nov. 9, 1960 INVENTOR. 3S 2,3 W\| L.IAM sLAC z-LE ATTORNEY United States Patent 3,040,550 STOP MOTION MECHANISM FOR CIRCULAR KNITTING MACHINES William R. Slagle, Glenilfer Clifton Road, Muizenberg-Cape, Unionof South Africa Filed Nov. 9, 1960, Ser. No. 68,278

4 Claims. (Cl. 6616,3)

This invention relates to a stop motion mechanism for circular knitting machines and more particularly to a stop mechanism operable during the knitting of the toe and heel of hosiery in event all or most of the needles are picked up or the dropper fails to come into operation after the amount of narrowing in the knitting of the heel and toe has taken place.

It is an object of the invention to provide a spring take-up arm co-acting with a contact arm in circuit with the stop motion switch of a knitting machine, the stroke of the take-up arm being varied by the tension of the yarn leading to the needles so that upon failure of the needles to maintain the proper tension on the take-up arm it will contact the contact arm to close the circuit and stop the machine.

A further object of the invention resides in providing a contact arm for co-action .with the yarn take-up arm which is adjustable to vary the distance between the two arms to insure instant contact between the arms if the stroke of the take-up arm rises above a predetermined height.

Other objects and advantages of the invention will be apparent during the course of the following specification.

In the accompanying drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

FIG. 1 is a diagrammatic perspective view of the stop motion mechanism,

FIG. 2 is a side elevational view of the same,

FIG. 3 is a top plan View of the same, and,

FIG. 4 is a section taken on line 4-4 of FIG. 2.

Referring to the drawing, the numeral 5 denotes a sup porting bracket which may be attached to the center post of a conventional circular knitting machine above the needles 6 of the needle cylinder. The bracket 5 is L- shape with the arm 7 having an upstanding bar 8 along its outer edge which extends beyond the inner end of arm 7 and the inner end of bar 8 is angularly bent at 9 with an aperture 10 therethrough for the passage of the yarn 11. The yarn is supplied from a conventional bobbin and after passing through aperture 10 it is trained between disks 12' of a tension device 13 mounted on bar 8, then over and under guide fingers 14 and 15 projecting from bar 8, through the aperture of a guide bracket 16 attached to bar 8' and then between disks 17 of a second tension device 18 adjacent the outer end of bar 8. A spring wire take-up arm 19 has one end fixedly attached, as at 20, to a block 21 attached to bar 8 and extends longitudinally of bar 8 in an upwardly direction with its free end disposed above the tension device 18 and has a loop 22 formed thereon for the passage of yarn 11. The yarn 11 after passing through loop 22 extends downwardly through an opening 23 in the outer end of arm 7 to the heel finger 24 above throat plate 25 which guides the yarn tothe needles 6 of the knitting machine. At the time the knitting machine starts to knit the heel and toe a cam on the machine raises half the needles out of knitting action and lifter picks are brought into operation raising one needle out of action at every reciprocation so that narrowing takes place during the first portion of knitting the heel and toe. The take-up arm 19 pulls backon the yarn as the needles are raised out-of action to take-up the slack yarn, which action is repeated at 19 having one end pivotally mounted, as at 27, to an insulation post 28 extending up from the bar 8 adjacent its inner end. The arm 26 is connected by a wire 29 with the stop motion switch of the knitting machine. The arm 26 is adjustably connected adjacent its free end to an upstanding insulation post 30 attached to bar 8 by a screw 31 extending through a longitudinal slot 32 formed in the post. The free end of arm 26 is provided with oppositely extending lateral contact fingers 33 eccentrically mounted on disks 34 rotatably secured to the free end by' a screw 35; One of the contact fingers extends over the free end of the take-up arm 19 and may be adjusted to control the distance between the take-up arm and contact finger. The take-up arm 19 is in circuit with the stop motion switch and co-acts with the contact arm 26 to close the circuit of the stop motion switch when the arm contacts the finger 33. The other contact finger 33 may be employed to control other operations of the machine and is independently adjustable.

In operation, when the knitting machine starts to knit the heel and toe, one half of the needles have been removed from operation, and one of the remaining needles in operation, after each reciprocation of the needles, is raised out of operation, thus allowing the take-up arm 19 to rise upwardly into closer relation to the contact arm 26. After the desired amount of narrowing in the knitting of the heel and toe has taken place the dropper is brought into operation which drops two needles on every reciprocation of the needles. The machine is then in a critical position for if the dropper fails to come into operation and drop the needles a smash-up will likely occur resulting in the breaking of needles and a great amount of damage to the machine. With my attachment it will be seen that when the dropperis due to come into operation the take-up wire will have risen until it is nearly in contact with the contact arm and should the dropper fail to 7 drop any needles the take-up arm will continue to rise and thus make contact with the finger 33 of the contact arm thus closing the circuit to the switch for stopping the machine before any damage can be done.

It is to be understood that the form of my invention herein shown and described is a preferred example of the same and changes in the shape, size and arrangement of the parts may be made Without departing from the spirit of the invention.

Having thus described my invention, I claim:

1. In a stop' motion mechanism for circular knitting machines, a contact arm in circuit with the stop motion switch of the machine mounted above the needle cylinder of the machine, a spring take-up arm having one end fixedly mounted and in circuit with the stop motion switch of the machine, the free end of said spring arm being disposed beneath said contact arm and having free sliding engagement with the yarn leading to the needles of the machine, a finger extending laterally from said contact arm transversely of the free end of said spring arm, and means adjustably mounting said finger to vary the distance between said finger and said spring arm.

2. In a stop motion mechanism for circular knitting machines as described in claim 1 including a tension device below the free end of said spring arm for tensioning the yarn leading to the free end to normally hold said spring arm from contact with said finger.

3. In a stop motion mechanism for circular knitting machines, a contactarm in circuit with the stop motion switch of the machine mounted above the needle cylinder of the machine, a spring take-up arm having one end fixedly mounted and in circuit with the stop motion switch disposed beneath said contact arm and having free sliding engagement with the yarn leading to the needles of the machine, a disk rotatably mounted on said contact arm above the free end of said spring arm and a finger eccentrically mounted on the side of said disk and extending laterally therefrom transversely of the free end of said spring arm.

4. In a stop motion mechanism for circular knitting machines as described in claim 3 including a second rotatable disk mounted on said contact arm opposite said first mentioned disk, and a second finger eccentrically mounted on said second disk and extending laterally therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 534,334 Kutz Feb. 19, 1895 2,147,275 Wachsman Feb. 14, 1939 12,407,773 Fletcher Sept. 17, 1946 2,669,855 Lebocy Feb. 23, 1954 FOREIGN PATENTS 602,142 France Aug. 17, 1925 

